To compare the time required for evaluation, the diagnostic accuracy and quality of conventional glass slide smears vs. ThinPrep smears in 365 women. Both smears were obtained at the same time using the Accellon Combi cervical biosampler. Histology served as the diagnostic "gold standard." The average screening time was 1 minute, 23 seconds, shorter per smear with the ThinPrep method as compared to the conventional glass slide (P < .001). Direct diagnostic agreement between the two smear methods was obtained in 311 of 364 evaluable smears (85.4%, kappa = .63). Despite the relatively high rate of "adequate but limited by absence of transformation zone components" observed with the ThinPrep method, the sensitivity and specificity of the ThinPrep method was slightly greater but not statistically significantly different than the conventional technique, irrespective of the disease categories (low and high grade squamous intraepithelial lesion and invasive cancer). The shorter time required to screen ThinPrep smears compared to conventional smears in this study was not sufficiently important to offset the current unit price for preparing ThinPrep smears.